1. Field of the Invention
This invention regards a cargo evaporation device for use when unloading ships. More particularly, it concerns a floating coupling unit arranged to connect to a ship, preferably at the ship's loading manifold, and which is provided with a submerged cargo evaporation device. The coupling unit is connected to a gas receiving installation via a pipeline.
2. Description of Related Art
It is well known that liquefied natural gas (LNG) is transported in a chilled state across great distances in purpose-built ships. At the receiving site, the liquefied gas is normally pumped from the ship and into storage tanks of a considerable size, whereupon the gas is evaporated prior to flowing into a distribution network.
Evaporation of natural gas from the highly chilled, liquid form into a gaseous form requires a significant addition of heat to the gas.
Thus, receiving installations for liquefied natural gas are relatively large, as the same time as the costs of building and operating such installations are significant.
In areas where no such receiving installations are provided, the gas cargo on the ship can not be unloaded immediately but at the rate of consumption of the gas.
It is known to use the carrier as a storage facility for the gas while it is being pumped into the gas receiving installation. Thus U.S. Pat. No. 6,089,022 concerns a ship for transport of liquefied natural gas, provided with gas evaporators. The evaporators are heated by seawater. The ship is designed to deliver evaporated natural gas to an onshore installation as the gas is used.
Consequently, in the case of installations according to prior art, each ship must be provided with a gas evaporation plant.
The object of the invention is to remedy the disadvantages of the prior art.